Just picked up a 2008 Cat 299C. Serial JSP00285. Machine does not want to boom up with the normal operation of the joystick. When I pull straight back, it does nothing (no change in rpm what so ever) However, If you boom down then tilt up, then boom up quickly (rotate the joystick counter clockwise), the boom will raise. As soon as you let off of boom up, the boom will drift down quickly. Raise function will continue to work until another function is selected, then it will have to lower-tilt-raise again before it will work. If I get the joystick in just the right position it will hold. All other functions work as they should. Machine was at CAT a year and a half ago and received a new joystick and control valve assembly. Fluid is full and clean, emergency valve beside the seat is all the way down. Any Ideas? Thanks in Advance
Does the bucket tilt always work OK in response to joystick movement.? Post a photo of the indicator panel in the upper RH corner of the cab. You might be lucky and have a panel that allows you to get into diagnostics.
No panel in the upper right-hand corner, just the blanked off cover. and yes, tilt both ways and boom raise works perfect every time.
In that case unfortunately you need someone with ET to hook up to the machine and look at the performance of the implement electronic controls.